Start with high-confidence mammal biology books, then narrow by subgenre or adjacent topics.
The Rise and Reign of the Mammals
Steve Brusatte
End of the Megafauna
Ross D E MacPhee, Peter Schouten
Field Guide to Mammals of Europe, North Africa and the Middle East
Stéphane Aulagnier, Patrick Haffner
The Rise of Mammals in Africa
Emmanuel Gheerbrant, Charlène Letenneur
I, Mammal
Liam Drew
Wolf Almanac
Robert Busch, Robert H. Busch
Rats
Robert Sullivan
Bats
Marianne Taylor
The Safari Companion
Richard D. Estes
A Naturalist's Guide to the Mammals of Southeast Asia
Chris & Loretta Shepherd
